Low electrical leakage support

ABSTRACT

A support for an electrical appliance is disclosed, which provides low electrical current leakage to ground. The support is made up of a metal track generally U-shaped in cross section, facing downward and suitable to be attached to a ceiling. The metal track has a small trolley track U-shaped in cross section also facing down and made of a polymer material supported inside the main track. A fixture carriage operates in the carriage track and an electrical trolley carrying electrical brushes operates in the trolley track. The trolley has spaced bus bars which make sliding contact with brushes on the trolley. The trolley itself is made of a dielectric material except for the brushes, springs and terminals. The trolley track is likewise made of a dielectric material, which produces a low current leakage from the electrical circuit to ground.

United States Patent Claxton et al.

[ Nov. 19, 1974 LOW ELECTRICAL LEAKAGE SUPPORT Inventors: Patrick H.Claxton, Brampton,

Ontario, Canada; Thomas A. Keenan, Erie, Pa.

Assignee: American Sterilizer Company, Erie,

Filed: Dec. 26, 1972 Appl. No.: 318,556

US. Cl. 191/33, 191/29 K, 191/22 R Int. Cl B60n l/04 Field of Search191/22 R, 23, 28, 29 R,

References Cited UNITED STATES PATENTS 8/1967 Martin l9l/23 R 10/1967Kilburg 7/1968 Hillmann... 11/1973 Ross ..191/23R Primary Examiner-M.Henson Wood. .lr. Assistant ExaminerD. W. Keen [5 7] ABSTRACT A supportfor an electrical appliance is disclosed, which provides low electricalcurrent leakage to ground. The support is made up of a metal trackgenerally U-shaped in cross section, facing downward and suitable to beattached to a ceiling. The metal track has a small trolley trackU-shaped in cross section also facing down and made of a polymermaterial supported inside the main track. A fixture carriage operates inthe carriage track and an electrical trolley car-- rying electricalbrushes operates in the trolley track. The trolley has spaced bus barswhich make sliding contact with brushes on the trolley. The trolleyitself is made of a dielectric material except for the brushes, springsand terminals. The trolley track is likewise made of a dielectricmaterial, which produces a low current leakage from the electricalcircuit to ground.

13 Claims, 7 Drawing Figures PATENTEL HUV 1 9 I974 SHEET 10F 2 g i N LOWELECTRICAL LEAKAGE SUPPORT OBJECTS OF THE INVENTION It is an object ofthe invention to provide a support arrangement for an electrical devicesuch as a surgical lamp wherein minimum electrical current leakageresults to the ground.

Another object of the invention is to provide a fixture with a minimumcurrent leakage fixture support which is simple in construction,economical to manufacture, and simple and efficient to use.

Another object of the invention is to provide an improved fixturesupport.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawing and more particularlypointed out in the appended claims, it being understood that changes maybe made in the form, size, proportions, and minor details ofconstruction without departing from the spirit or sacrificing any of theadvantages of the invention.

GENERAL DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the fixturesupport according to the invention.

FIG. 2 is an exploded view partly in cross section of the fixturesupport shown in FIG. 1.

FIG. 3 is a top view partly in cross section of the trolley.

FIG. 4 is a side view of the trolley.

FIG. 5 is an end view partly in cross section of the trolley.

FIG. 6 is a longitudinal cross sectional view of the trolley track.

FIG. 7 is a side view of the tracks.

DETAILED DESCRIPTION OF THE DRAWINGS Now with more particular referenceto the drawings, the device according to the invention is made up mainlyof the main track 10, the trolley track 11, the trolley 13, and thecarriage 12 which supports the electrical device which is in the exampleshown, the lamp 14.

The main track 10 and the trolley track 11 are both made in the form ofchannels opening downwardly. The trolley track 11, however, is muchsmaller in cross section than the main track 10 and the trolley track 11is made of a dielectric material having bus bars supported in it to makecontact with the brushes on the trolley to transmit electricity to thecarriage l2 and thence to the lamp 14. The trolley itself is made ofdielectric material, such as a molded polymer for example. Since thetrolley track 11 and the trolley 13 are made of molded polymer, aminimum electrical leakage results from the electrical lines and busbars to the carriage l2 and thence to the external parts of the lamp l4and track 10.

The main track 10 may be made of a metal and it could be extruded from asuitable metallic material and supported on the ceiling of a room, asindicated in FIG. 1. The main track has spaced flanges 34 and 35 whichhave inwardly directed legs 30 and 31 fixed to their lower ends andbeads 36 and 37, which form tracks for the wheels 28 of the carriage.

The trolley track 11 is generally in the same form as the main track 10but is much smaller. The trolley track 11 is made of a dielectricmaterial and has flanges 32 and 33 fixed to the intermediate web 43. Thebus bars 22 and 23 are set in recesses under beads 25 and 26 and 27 and28 respectively on the inner side of the flanges 32 and 33. A bus bar 24is supported on the inner surface of the web 43 of the trolley track.The inwardly directed ends 40 and 41 of the trolley track underlie thetrolley 13 and prevent the brushes l8, 19, 55 and 56 from separatingfrom the bus bars 22, 23 and 43.

The trolley 13 is made of two L-shaped angle sections 16 and 17 whichare held together by bolts 29. The angle sections are molded, orotherwise formed, from a dielectric material such as a polymer. Theangle sections 16 and 17 have pockets 41 and 42 integrally formedthereon and these pockets receive the springs 20 and 21. The springs 20and 21 are U-shaped leaf springs that have their inner end resting onthe inner surface of the opposite angle section and the inner ends ofthe U-shaped springs are electrically connected to the electricalterminals 45 and 46. Springs 55 and 56 are connected to terminals 44 and47. Bus bars 22 and 23 are connected to a source of electricity by lines69 and 70. The electrical terminals 45 and 46 are in turn connected tothe lines 65 and 66 in the carriage 12 and conduct electricity to thelamp 14 from the bus bars 22 and 23 through the trolley. The outer endsof the springs 20 and 21 have the brushes 19 and 18 respectively fixedto them and the brushes 18 and 19 extend outwardly through openings inthe pockets 41 and 42 and are urged outwardly into sliding engagementwith the bus bars 22 and 23. Springs 55 and 56 act as brushes and arefixed to the upper edge of the trolley sections 16 and 17 and areelectrically connected to bus bar 24. Springs or brushes 55 and 56 formsliding engagement with the bus bar 24. Springs or brushes 55 and 56 areconnected to terminals 44 and 47, which will in turn be connected to thecarriage 12. A ground circuit is formed from bus bar 24, brushes 55,terminals 44 and 47 to lines 67 and 68.

When the device shown herein is assembled, the main track 10 will befixed to a ceiling, as shown in FIG. 1, and the trolley track 11 willhave its web fixed to the web of the main track 10 so that the trolleytrack is in relation with the main track as shown in FIG. 2, with theflanges of the trolley track spaced inwardly from the flanges of themain track so that the wheels 28 of the carriage can operate below thetrolley track. The trolley 13 will be fixed to the carriage by means ofthe terminals 44, 45, 46 and 47 so that the trolley moves alongcoextensively with the carriage. The brushes 18, 19, 55 and 56 willengage the bus bars 22, 23, and 24 and thereby conduct electricity fromthe lines 50 and 51 to the fixture 14 through the carriage.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with theappended claims.

The embodiments of the invention in which an exclusive property ofprivilege is claimed are defined as follows:

1. A support for an electrical system comprising a main first channeltrack having means including a first web and spaced downwardly extendingfirst and second flanges attached to said first web,

second channel means supporting bus bars on said main track,

said second channel means having a second web, a

third flange and a fourth flange,

a first bus bar supported on said second web and a second bus barsupported on said third flange and a third bus bar supported on saidfourth flange,

means for connecting said bus bars to a source of electricity,

said second channel means comprising dielectric means between said busbars and said main track whereby a low electrical leakage resultsbetween said bus bars and said track.

2. The support recited in claim 1 wherein a carriage is supported on acarriage track means,

and trolley means attached to said carriage,

brush means on said trolley means making electrical contact with saidbus bars whereby electrical means supported on said carriage isconnected to said electrical means connected to said bus bars.

3. The support recited in claim 2 wherein said trolley is made ofdielectric material.

4. A support for an electrical device having a carriage and a trolleysupported on said carriage,

said support comprising a main track having a web adapted to be attachedto a ceiling,

a first flange and a second flange fixed to said web and extendingdownwardly therefrom in spaced relation to each other,

means on said first flange and on said second flange for supportingwheels attached to said carriage,

a fixture supported on said carriage,

a trolley track having a web disposed generally parallel to said maintrack web and supported thereon,

a third flange and a fourth flange spaced from each other and fixed tosaid trolley track web extending downwardly therefrom,

a first bus bar and a second bus bar made of electrical conductivematerial and fixed to said third flange and to said fourth flangerespectively,

.said trolley track being made of a dielectric material.

5. The support recited in claim 4 wherein said trolleyv track is made ofa molded thermoplastic material,

said trolley track and said third flange and said fourth flange are madeintegral with each other whereby a low electrical leakage results fromsaid trolley to said main track.

6. A support for an electrical appliance providing minimum leakage ofelectricity from an electrical fixture comprising a carriage track inthe form of an inverted channel adapted to be supported on a ceiling,

carriage supporting means for supporting a fixture carrying carriage onsaid track for movement thereon,

a trolley track in the form of an inverted channel smaller in crosssection than said carriage track and received in said carriage track andsupported therein,

said trolley track being supported above said carriage supporting means,

said trolley track being made of a dielectric material,

electrical bus bar means fixed in said trolley track and adapted toslidably engage brush means supported on a carriage for slidablyengaging said contact means whereby electricity is transferred from asource of electricity to said contact means and to said fixturesupported on said carriage.

7. The support recited in claim 6 wherein a carriage is supported onsaid carriage track,

and said brush means is supported on its trolley,

said trolley being slidably received in said trolley track,

said trolley being made of a dielectric material with said brush meanssupported thereon.

8. The support recited in claim 7 wherein said contact means comprisesbus bars fixed to the inside of said trolley track and extending alongthe inside edges of said downwardly facing channel.

9. The support recited in claim 6 wherein said trolley comprises amember T-shaped in cross section and made of dielectric material andslidably supported in said trolley track,

recesses in said T-shaped member,

spring means in said recesses,

said brush means being supported on said spring members and urged intocontact with said bus bar members by said spring.

10. A support for an electrical device comprising a main track U-shapedin cross section,

a trolley track U-shaped in cross section,

said trolley track being substantially smaller in cross section thansaid main track and disposed in said main track,

said trolley track having a web with two spaced flanges fixed to saidweb,

said main track having a web with two spaced flanges fixed to said web,

said trolley track web resting on said main track web and said trolleytrack flanges being spaced inwardly from and generally parallel to saidmain track flanges,

said trolley track being made of a dielectric material,

means for supporting said main track and said trolley track on aceiling,

a carriage having spaced wheels,

first support means on said main track flanges for supporting saidcarriage wheels,

said carriage wheels resting on said support means,

a trolley,

said trolley having spaced laterally extending first and second brushmeans,

means on said trolley track guiding said trolley therethrough,

spaced bus bar means fixed to the inside surface of said trolley trackflanges,

said bus bar means being adapted to be connected to a source ofelectricity,

said brushes on said trolley each slidably engaging one of said busbars,

electrical connection means for connecting said brushes to electricalcircuit means in said carriage.

11. The support recited in claim 10 wherein a third bus bar is fixed tosaid web of said trolley track,

and third brush means is supported on said trolley slidably engagingsaid third bus bar means,

and electrical means connecting said third bus bar with fixture meanssupported on said carriage.

12. The support recited in claim 10 wherein said trolley track is madeof a single integral thermoplastic member.

13. The support recited in claim 12 wherein said trolley is made of adielectric material.

1. A support for an electrical system comprising a main first channeltrack having means including a first web and spaced downwardly extendingfirst and second flanges attached to said first web, second channelmeans supporting bus bars on said main track, said second channel meanshaving a second web, a third flange and a fourth flange, a first bus barsupported on said Second web and a second bus bar supported on saidthird flange and a third bus bar supported on said fourth flange, meansfor connecting said bus bars to a source of electricity, said secondchannel means comprising dielectric means between said bus bars and saidmain track whereby a low electrical leakage results between said busbars and said track.
 2. The support recited in claim 1 wherein acarriage is supported on a carriage track means, and trolley meansattached to said carriage, brush means on said trolley means makingelectrical contact with said bus bars whereby electrical means supportedon said carriage is connected to said electrical means connected to saidbus bars.
 3. The support recited in claim 2 wherein said trolley is madeof dielectric material.
 4. A support for an electrical device having acarriage and a trolley supported on said carriage, said supportcomprising a main track having a web adapted to be attached to aceiling, a first flange and a second flange fixed to said web andextending downwardly therefrom in spaced relation to each other, meanson said first flange and on said second flange for supporting wheelsattached to said carriage, a fixture supported on said carriage, atrolley track having a web disposed generally parallel to said maintrack web and supported thereon, a third flange and a fourth flangespaced from each other and fixed to said trolley track web extendingdownwardly therefrom, a first bus bar and a second bus bar made ofelectrical conductive material and fixed to said third flange and tosaid fourth flange respectively, said trolley track being made of adielectric material.
 5. The support recited in claim 4 wherein saidtrolley track is made of a molded thermoplastic material, said trolleytrack and said third flange and said fourth flange are made integralwith each other whereby a low electrical leakage results from saidtrolley to said main track.
 6. A support for an electrical applianceproviding minimum leakage of electricity from an electrical fixturecomprising a carriage track in the form of an inverted channel adaptedto be supported on a ceiling, carriage supporting means for supporting afixture carrying carriage on said track for movement thereon, a trolleytrack in the form of an inverted channel smaller in cross section thansaid carriage track and received in said carriage track and supportedtherein, said trolley track being supported above said carriagesupporting means, said trolley track being made of a dielectricmaterial, electrical bus bar means fixed in said trolley track andadapted to slidably engage brush means supported on a carriage forslidably engaging said contact means whereby electricity is transferredfrom a source of electricity to said contact means and to said fixturesupported on said carriage.
 7. The support recited in claim 6 wherein acarriage is supported on said carriage track, and said brush means issupported on its trolley, said trolley being slidably received in saidtrolley track, said trolley being made of a dielectric material withsaid brush means supported thereon.
 8. The support recited in claim 7wherein said contact means comprises bus bars fixed to the inside ofsaid trolley track and extending along the inside edges of saiddownwardly facing channel.
 9. The support recited in claim 6 whereinsaid trolley comprises a member T-shaped in cross section and made ofdielectric material and slidably supported in said trolley track,recesses in said T-shaped member, spring means in said recesses, saidbrush means being supported on said spring members and urged intocontact with said bus bar members by said spring.
 10. A support for anelectrical device comprising a main track U-shaped in cross section, atrolley track U-shaped in cross section, said trolley track beingsubstantially smaller in cross sectIon than said main track and disposedin said main track, said trolley track having a web with two spacedflanges fixed to said web, said main track having a web with two spacedflanges fixed to said web, said trolley track web resting on said maintrack web and said trolley track flanges being spaced inwardly from andgenerally parallel to said main track flanges, said trolley track beingmade of a dielectric material, means for supporting said main track andsaid trolley track on a ceiling, a carriage having spaced wheels, firstsupport means on said main track flanges for supporting said carriagewheels, said carriage wheels resting on said support means, a trolley,said trolley having spaced laterally extending first and second brushmeans, means on said trolley track guiding said trolley therethrough,spaced bus bar means fixed to the inside surface of said trolley trackflanges, said bus bar means being adapted to be connected to a source ofelectricity, said brushes on said trolley each slidably engaging one ofsaid bus bars, electrical connection means for connecting said brushesto electrical circuit means in said carriage.
 11. The support recited inclaim 10 wherein a third bus bar is fixed to said web of said trolleytrack, and third brush means is supported on said trolley slidablyengaging said third bus bar means, and electrical means connecting saidthird bus bar with fixture means supported on said carriage.
 12. Thesupport recited in claim 10 wherein said trolley track is made of asingle integral thermoplastic member.
 13. The support recited in claim12 wherein said trolley is made of a dielectric material.